The microbially or biocatalytically mediated conversion of biomass, e.g. cellulose or starch, to provide technically raw materials, is an important alternative to fossil fuels and is becoming of increasing importance in view of the future exhaustion of fossil fuels. Therefore it is important to have at hand as many biologically catalysed reactions as possible to allow for the use of biological or biocatalytical processes for their production.
Acrylylcholine, which is industrially more commonly referred to as qDMAEA, the quaternary salt of 2-(N,N-dimethylamino)ethyl acrylate, and methacrylylcholine, as well as DMAEA or DMAEMA, are (meth)acrylic monomers which find extensive use for the manufacture of polymers. Particularly water-soluble homopolymers or copolymers with other polymerisable monomers such as for instance (meth)acrylamide or n-vinylpyrrolidone or hydroxyethyl acrylate, and the like, are used in the manufacture of such polymers. These polymers find use in a number of applications, particularly for use as flocculating agents in the treatment of water; but also for other purposes, e.g. as thickeners, as retention aids in binders in the paper industry, as dispersants or as aids in the transfection of microorganisms with nucleic acids, such as DNA, and the like.
Choline (2-hydroxyethyltrimethylammonium) is a quaternary amino alcohol that occurs widely in living organisms as a constituent of certain types of phospholipids and in the neurotransmitter acetylcholine. It is also part of the daily diets as it is comprised in many foods.
DMAE [2-(N,N-dimethylamino)ethanol] also occurs widely in living organisms and is, for example, a precursor in the biosynthesis of phosphatidylethanolamine.
Acrylic acid and methacrylic acid are monomers used extensively to manufacture polymers, either as homopolymers usually of salts of the acid, such as sodium acrylate or ammonium acrylate, or a copolymers with other polymerisable monomers such as acrylamide and the like. These synthetic polymers are used for a variety of applications including flocculating agents for water treatment; coatings, finishes and binders for the paper, textile and leather industries; and use in the manufacture of paint, polishes and adhesives in the production of superabsorbents and dispersants and the like.
The metabolic synthesis of acrylic acid was described by Dalal et al (Biosources Digest vo. 2 p 89 to 97) in 1980. The authors reported that acrylyl CoA is hypothesised to be an intermediate in the anaerobic dehydration of lactate in Megasphera elsdenii and that it occurs following β-hydroxypropionyl CoA dehydration in Clostridium propionicum. They also suggested that using resting cells of C. propionicum acrylate accumulation was observed with propionate as the substrate. A metabolic scheme for the synthesis of acrylyl CoA is given in Scheme 1.

More recently, a few ways for the biosynthetic synthesis of acrylate and acrylate esters have been described, e.g. in WO 02/042418 A2 or WO 02/42471 A2, see also WO 00/71738 for the synthesis of acrylic acid.
Neither of these documents describes the possibility of manufacturing 2-(N,N-dimethylamino)ethyl acrylates or (methacrylates) or cholinylacrylates or -methacrylates(acrylylcholine or methacrylylcholine hereinbefore and hereinafter), and they usually require a combination of an acrylyl CoA-hydrolase and a lipase activity to first produce free acrylate from acrylyl CoA that is then converted into an ester of an aliphatic alcohol by means e.g. of a lipase.
On the other hand, EP 0 250 325 and WO 00/43348 describe chemical processes for the synthesis of acrylylcholine starting e.g. from 2-dimethylaminoethyl-acrylate and methyl chloride, while JP 9255640 and JP 6279371 describe methods for the chemical synthesis starting either from acrylonitrile reacted with sulphuric acid, via acrylamide sulphate as an intermediate and then with choline chloride, or for example reacting acrylic acid with choline chloride in the presence of an acid catalyst in toluene.
Instead of these chemical reactions, a biocatalytic reaction would, however, be highly desirable in order to provide the final step in an integrated biosynthetic approach that may also make use of renewable biomass.
Acrylic and methacrylic acid are known substrates of the enzyme S-acetyl CoA synthetase (S-acetyl coenzyme A synthetase, acetate thiokinase or acetate:CoA ligase) (EC 6.2.1.1), however, the products found did not in the main appear to correspond to the acyl CoA thioesters—instead binding of two equivalents of CoA took place via both Michael addition to the double bond and thioester formation via the carbonyl of the acid, and thus a bis-adduct was found to be formed (see e.g. Patel and Walt, Anal. Biochem. 170, 355-60 (1988)). The bis-adduct has the following formula:

Against this background, it would be highly desirable to provide a biological process for the synthesis of (meth)acrylylcholine and/or DMAE(M)A that is simple and/or a real alternative to the present chemical methods and forms a basis also for the integration into a more general biotechnological process, e.g. finally making use of regenerative resources.